Pluvial Flood Prevention
Pluvial Flood Prevention
Infiltration basin as an element of blue-green infrastructure © M. Illgen/Department of Urban Water Management RPTU
INTRODUCTION
The AMAREX work package 2 "functional extension of blue-green infrastructure (BGI) for heavy rainfall prevention" is being worked on by the Department of Urban Water Management at the RPTU Kaiserslautern-Landau. Blue-green infrastructure refers to various measures for the natural handling of rainwater in settlements. Through rainwater utilization, local infiltration and evaporation, high and rapid rainwater discharges are to be reduced or avoided. Positive effects of BGI are improved groundwater recharge and reduction of heat stress through evaporative cooling. However, the effect of BGI on heavy rainfall prevention is limited, because BGI is not technically designed for flooding-relevant heavy rainfall events.
With the expected increase in extreme heavy rainfall events as an effect of climate change, urban flood prevention is a highly relevant municipal task. In this work package, it will be investigated and evaluated what effect decentralized BGI for flood prevention can have if they are functionally adapted and optimized as BGI+ to the requirements of heavy rain prevention. For this purpose, the practical planning and implementation potentials will be investigated and evaluated in pilot areas.
Section of a heavy rainfall hazard map simulated with a flood model © Department of Urban Water Management RPTU
IDEAS
BGI+ must first be clearly defined from a technical point of view. This is done by developing a catalogue of measures to describe the basic application and operational requirements of BGI+ systems. Furthermore, it will be investigated where and under which boundary conditions BGI+ can be located in urban areas and how flooding hazards during heavy rainfall can be reduced. For this purpose, a geographic information system (GIS) and the corresponding geographic data (digital terrain model, cadastral and area information) are used to identify the area potentials of BGI+ and local depressions as potential flooding areas for a study area in Berlin. Subsequently, a hydraulic flood model is created for the study area, which is also used to represent the BGI+. Comparative model simulations with and without BGI+ can be used to determine the extent to which BGI+ can reduce flooding hazards.
The special feature of the integral approach in AMAREX is that the results of work package 2 together with the results of work packages 3 and 4 are transferred into a web tool. After the end of the project, municipalities and authorities will have an effective tool at their disposal with which they can assess the potential of BGI+ for the prevention of flooding and heat stress for their own study areas.
IMPLEMENTATION
A catalog of measures with a basic description and technical definition was created for the BGI+ systems. A first draft of the catalogue can be found here. The detailed effect of the systems for flood reduction in the event of heavy rainfall was investigated using simulations. Based on the results of the detailed impact assessment, the methodology for the simplified effect (BGI+ effects for heavy rainfall prevention) was developed for new study areas. This is currently being transferred to the user web tool.
